Automatic electrical cut-out



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Patented Mar. 29,1921.

H. w. FREESE. AUTOMATIC ELECTRICAL GUT-OUT. APPLICATION FILED NOV.20,1918.

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Erman UNITED STATES PATENT "OFFICE.

HERMAN W. FREESE, OF CHICAGO, TLLINOIS, ASSIGNOR TO HERBERT AJPARKYN, OF

\ CHICAGO, ILLINOIS.

AUTOMATIC ELECTRICAL CUT-OUT.

Application filed November 20, 1918.

after the current has traversed the same apredetermined length of time,in order that the undue heating of the electrical device located in thecircuit and operated by the current traversing the same, shall beavoided, my invention having been devised for use more particularlywhere relatively weak electric currents are employed,- as, for example,in the operation of solenoid switches.

My primary object is to provide a simple, economical and positivelyoperating construction for accomplishing the above purpose.

Referring to the accompanying drawings2- Figure 1 is a face view ofapparatus embodying my invention; and Fig. 2, a section taken at theline 2-2 on Fig. 1, and viewed in the direction of the arrows.

Generally stated, my invention involves the use of a thermostaticelement which is subjected to the heat generated by the current to becontrolled and through the medium of which the circuit is opened andclosed.

In the particular illustrated embodiment of my invention. I provide abox 3 connected at opposite ends with pipe sections l and 5 into whichthe electric current conducting wires 6 and 7 at one side of a circuitto be controlled, extend into the box. the wire 6 connecting with abinding post 8 and the wire 7 with a binding post 9. The bracket 10carrying the binding post 9 is mounted on a block of insulatingmaterial'll secured to the casing 3 as by a screw 12. this bracketcarrying a contact member 13 the end face of which is of frusto-conicalshape as represented at 14. The contact 13 cotiperates with thethermostatic member represented at 15, this member being shown as formedof a pair-of flatwise opposed bars 16 and 17 welded together and securedat one end. as indicated at 18, to 'a block 19 secured to theSpecification of Letters Patent.

Patented Mar. 29, 1921.

Serial No. 263,328.

insulating plate 11. The opposite, free, end of the thermostat 15, thelatter being curved as represented, presses against the contact 13 inthe normal condition of the structure to close the circuit at this pointby reason of the connection with the device 15, of a wire forming a partof the circuit as herein-' after explained. The bars 16 and 17 may bemade of any desirable material provided they present differentco-efficients of expansion in order that the free end of thethermostatic element will be drawn toward its fastened end and in adirection to disengage it from the contact 13'. when the thermostat 15is heated to a predetermined degree. By way of example the bar 16 maybeconstructed of copper and the bar 17 of zinc.

The thermostatic element 15 is wound with current-conducting wire forsubjecting it to the heat of the current, this wire being represented at20. It is preferred that this wire 20 be what is known as magnet wire,either silk or cotton covered. and that one end thereof be connectedwith the binding post 8 and its opposite end. represented at 21,electrically connected with the bar 17.

It will be readily understood from the foregoing that in the passage ofthe current through the wire 20, this wire forming a part of the circuitto be controlled by the cut-out, the thermostatic element 15 will becomeheated and will move out of contact with the electrical contact 13 andthus break the circuit. Furthermore. it will be understood that thelength of time which elapses before the circuit is broken, as statedabove. will depend upon the strength of current traversing the wire 20and the gage of this wire and thus the device may be constructed to holdthe circuit-closed for any desired predetermined length of time withincertain limits.

In the use of the cut-out in certain connctions it is desirable thatupon the breaking of the circuit between the element 15 and the contact13, these parts be held out of of the bracket 23 and a pin 25 on the pin22,

into the space between the contact 13 and the free end of thethermostatic element when the latter is moved out of engagement rangedthat the spring 2 does not, in the normal condition of the structure,operate to force the element 15 ,out of engagement with the contact,13'.

. static device, and mechanical means sep Vhile I have illustrated anddescribed a particular construction embodying myinvention, I do not wishto be understood as intending to limit it thereto as the same may bevariously modified and altered without departing from the spirit of myinvention, it being my intention to claim my invention as fully andcompletely as the prior st'ate of the art will permit. 1 Y

'hat I claim as new and desire to secure by Letters Patent, is

1. In combination with an electrical circuit, separable contactsinterposed therein, thermostatic means for separating'said contacts whenthe heat to which the thermostatic means is subjected reaches apredetermined degree, means for subjecting said thermostatic means toheat generated by the current in traversing said circuit, and mechanicalmeans separate from the parts which serve to close the circuit movableautomatically to a position for maintaining said contacts out ofengagement with each other upon the separating of said contacts by theaction of said thermostatic means.

2. In a device of thecharacter set forth,

the combination of separable contacts, a

thermostatic device operating to separate said contacts when saiddevice. is heated, an electric-current-conducting element forinterposition in an electrical circuit and adapted to be heated by thecurrent traversing the circuit to be controlled by said thermostaticdevice and"operating-to heat said theremo- 'ment with each other uponthe separating of said contacts by the action of said thermostaticdevice.

In combination with an electrical circuit, separable contacts interposedtherein,

thermostatic means for separating said contacts when the heat to whichthe thermostatic means is subjected reaches-a predetermined degree,means for subjecting said thermostatic means to heat generated by thecurrent in traversing said circuit, and springdmpelled means separatefrom the parts which serve to close the, circuit, movable automaticallyto a position for maintaining said contact-s out of engagement with eachother upon the separating of said contacts by the action of saidthermostatic means. a

4. In combination with an electrical circuit, separable contactsinterposed therein, thermostatic means for separating said contacts whenthe heat to which the thermo-' static means is subjected reaches apredetermined degree, means for subjecting said thermostatic means toheat generated by the current in traversing said-circuit, a reciprocablysupported member movable into a position for maintaining said contactsout of engagement with each other upon the separat-" ing of saidcontactsby the actionof said thermostatic means, and a spring for movingthesaid member into said position. x

5. In combination with an electrical circuit, separable contactsinterposed therein, thermostatic means for separating said contacts whenthe heat to. which the thermostatic means is subjected reaches apredetermined degree, means for subjecting said thermostatic means toheat generated by the current in traversing said circuit, and'inea nspositioned adjacent the abutting surfaces'of said contacts and adapted,upon the separating of said contacts, by the action of said thermostaticmeans, to be automatically moved into a position between said contacts,the surfaces of said contacts opposing said last-named means convergingaway from said means;

' HERMAN W. FREESE.

